PPT Slide
How can you decide you have detected a QTL?
Test statistic (e.g. F or LR) > Critical value
Need to control Type I error rate
= % of false positives (e.g. 1% / 5% / 10%)
Hypothesis testing complicated by:
- Large # tests performed (many markers, QTL positions)
- At 5% significance, 5% of tests will be significant even if no QTL exist
- Tests on the same chromosome are dependent
- Bonferroni adjustment doesn’t work
- Standard critical values (Table F values) don’t apply
- Need to correct significance thresholds for multiple testing
to avoid large % of false positives